Mechanisms of noise sources in microelectromechanical systems

Estimation of stride length in level walking using an inertial measurement unit attached to the foot: A validation of the zero velocity assumption during stance

“…To do so, an estimate of the IMU orientation in the global reference frame is needed (Sabatini et al, 2005;Schepers et al, 2007). However, the procedure described above is complicated by a number of factors: (a) a drift is commonly present when integrating the accelerometer and gyroscope signals, mostly due to thermal-mechanical and electronic noise, introducing an error in the displacement estimations, which is nonlinearly related to the integration time (Djuric, 2000;Thong et al, 2004); (b) the determination of the IMU orientation with respect to the global reference frame from gyroscopic and accelerometer data is not trivial (Woodman, 2007) and (c) in the integration of the coordinate accelerations an estimate of initial velocity needs to be provided.…”

Numerical double integration of acceleration measurements in noise

“…Djuri c [4] has made a detailed study of the mechanisms of noise sources in microelectromechanical systems (MEMS), concluding that the noise in an accelerometer can be modelled as coming from two sources: (i) thermal-mechanical noise and (ii) transistor noise, although it was also noted that more work is required for a full understanding. Pang and Liu [5] have looked at characterising the performance of a particular accelerometer when used in a robotic system.…”

A new approach to IR bimaterial detectors theory

“…The performance of BMDs is influenced by various noise generation mechanisms [19,20]. These mechanisms include noise in the readout circuits and the intrinsic cantilever noise.…”

“…As previously stated, a BMD can be regarded as a mechanical oscillator characterized by its resonant frequency x 0 and the Q-factor [19,20]. On the other hand, its operation is based on temperature increase induced by heat absorption which depends on thermal conductance of the structure, G th .…”